Inhibitor for gasoline



Patented Oct. 27, 1942 2,300,246 INHIBITOR FOB GASOLINE Joseph A.Chenicek and Chicago, Ill., assignors note Company, Chicago,

Delaware BobertH. Itosenwald, to Universal Oil ProdllL, a corporation ofNo Drawing. Application October 27, 1939, Serial No. 301,636

Claims- (01.44-45) This invention relates to a method (or stabilizingolefin-containing hydrocarbon oils and more particularly crackedgasoline of petroleum orig against deterioration and loss of valuableproperties on storage. Gasolines from other sources may also be treatedaccording to the present invention, as may other hydrocarbon fractionssuch the polymerization of northe reiorming of naphthas,

as those produced by mally gaseous oleflns, etc.

More particularly method for stabilizing olefin-containing gasolineduring storage in respect to valuable properties such as color,antiknock value and low gum content which tend to depreciate because ofthe action of oxygen upon the oleflns in said gasoline.

The cracking and reforming of petroleum oils to produce additionalyields of valuable motor fuel or to improve the antiknockcharacteristics of straight-run gasolines and naphthas has beenpracticed to a large extent during recent years. Furthermore, processeshave been developed for polymerizing the normally gaseous olefinscontained in cracking plant gases to produce substantial yields of highoctane number blending fluid. All of the products thus produced, whetherby cracking, reforming or polymerization, contain substantial amounts ofoleflnic hydrocarbons which tend to form peroxides and gums and todepreciate in antiknock quality, color, odor, etc. when stored in thepresence of even minor amounts of oxygen. The use of inhibitors has beenpracticed to prevent such reactions and many types of compounds havebeen suggested for this purpose, including aminophenols, fractions ofwood tar, polyhydroxyphenols, etc.

In one specific embodiment the present invention comprises a method fortreating unstable olefin-containing gasolines to preserve their valuableproperties in respect to gum content, color and antlknock properties byadding thereto minor quantities of allnvl ethers of aminophenols oi thegeneral structure:

wherein R is either a hydrogen atom or an alkyl group, and R is an alkylgroup.

the invention concerns a The properties desirable in a gasoline guminhibitor are as follows:

(a) Solubility in the gasoline to a degree in excess of the maximumconcentration in which it is likely. to be used.

(1:) High degree of potency so that relatively small concentrations canbe used.

(c) Insolubility or relatively low solubility in water or aqueousalkaline 0r acidic solutions with which the gasoline is likely to comein contact.

(d) Either normally liquid or having a high degree of solubility in anon-aqueous, gasolinemiscible solvent thus increasing the ease ofhandllng and addition to the gasoline.

(e) Nonreactive with tanks, fittings, lines, engine parts, etc., withlikely to come in contact.

(f) 01 light color, and ing no objectionable color or odor when added,or during storage.

The inhibitors of the present invention to a large extent fulfill theserequirements.

A representative group of the compounds which are useful are given inthe example.

The alkom group and the N-substituted alkyl group may contain anysuitable alkyl group such as normal, secondary, or tertiary allqlgroups, and may be either the same or difierent in molecular weight andstructure.

The compounds may be prepared by reacting the sodium salt of nitrophenolwith an alkyl halide of the desired molecular weight and structurefollowed by reducing the nitro ether thus formed to the amino ether. Theamino ether may then be reacted with an alkyl halide to produce theN-substituted amino ether. Another method oi preparing the compounds isto react the sodium salt of an N-substituted aminophenol with an alkylhalide to produce the N-substituted amino ether.

The followin examples are given to illustrate the usefulness andpracticability of the compounds characterizing the invention but shouldnot be construed as limiting it to the exact compounds given therein.

The inhibitor effectiveness 01 the compounds was measuredby means of theoxygen bomb induction period. In this test a sample of gasoline with andwithout 0.01% by weight of the added imparting or developto the gasolinewhich the gasoline is curred was measured.

compound was heated a pressure recording desodium hydroxide solution.The

data obtained are shown in Table II.

Tun: II Enect of caustic and water on aminophenul I I ether;

Cu dish gum, mg./100 cc. Induction period, minutes Per ggfi .InhibitorWater Caustic Water Ciustic Water Caustic min wash wash wash wash washwash Blank gasoline 00 11a 19 so 70 so Commercial inhibitor A 7 12 80340 285 105 17 79 Commercial inhibitor B 9 14 300 305 210 0 27p-Aminophenyl isobutyl ether 49 18 19 360 325 280 9 l8 p-Aminophenlisopropyl ether 25 25 25 305 280 260 7 7 pn-Butyl g-phenyl t-butyl ethe12 10 350 310 310 ll 4 pn-Butylamino henyl n-butyl ether 21 35 23 310310 305 0 0 p- Isopropylamino hen lisopropyl ether" 10 17 10 28) 265 2403 5 p-(Isonmylamino)-p eny t-butylether 8 9 11 315 295 285 4 0 Vicewhereby the interval of time between t initiation o! heating theinduction period.

TABLE I Inhibitor ratios of various p-alkylaminophenyl ethers InductionN 0. Compound .Minutes Blank gasoline 85 1 p-(n-Bntylamino)-plienylt-butyl ether. 410 2 p-(laosmylaminoyghenyl t-butyl other. 375 3p-Aminophonyl iso utyl ether 205 4 p-gn-Butylaminoyphenyl n-butyl ether18g 5 pn-Butylamino)-phenyl ally] ether 17a 6 p-(Methylamino)-phenylisobutyl ethcr 170 7 p-Aminophenyl isopropyl ether 165 8 p-Isoamylnmino)- henyl sec-butyl ether 165 9 ppropylamino -phenylisopropyl other.-. 165 10 ppropylamino henyl t-butyi ether 165 11pn-Butylaminogenyl isobutyl other.-- 155 12 p-(n-Butylamino -phe nylsec-butyl ML. 155 13 pn-Butylamino)- henyl isoamyl other-.- 155 14ppropylsminoyl'iehenyl isobutyl ether 150 15 p-(Isosmylsmino)-p nyln-bntyl other-.- .150 16 p-Aminophenyl nrogy] other 145 17 ppropylsmino-p enyl sec-butylether 145 18 pn-Butylaminog-pheny ethei ether 145 19pn-Butylamino -pheny isogropyl ethe 140 20 psoamylamino)- henyl iso utylether 140 21 p-(Isopropylsminof-ghenyl isoamyl other 140 22p-Aminophenyl met yl ether 135 23 p-Aminophenyl n-amyl ether 135 24psoarnylaminog-phenyl isopropyl ether 135 25 p-(Isoamylamino henylisoamyl ether. 135 26 p-Aminophenyl et yl ether. 130 27 p-Aminophenylsec-butyl ether 130 As further evidence 01 the usefulness of thecompounds of the present invention, several representative compoundswere compared with two commercial inhibitors. Suilicient amounts of thevarious compounds were added to a gasoline to give an induction periodof the same order of figure. The copper. dish gum and induction periodswere determined before and after shaking the samples with water and withdilute (1%) resultsindicate that the compounds of this invention arerelatively insoluble in water and sodium hydroxide, being superior inthis respect to the commercial inhibitors with which they are compared.Translated into terms of commercial practice, these data indicate thatthe inhibitors when presentin gasoline stored in tanks containing wateror alkaline aqueous solutions will not be removed thereby, but willcontinue to protect the gasoline from the deleterious eifects ofoxidation.

We claim as our invention:

1. An inhibitor for cracked ing essentially p-(n-buty1amlno)-phenylt-butyl ether.

2. An inhibitor for cracked gasoline comprising essentiallyp-(n-butylamino) -phenyl n-butyl ether. I

3. A process for stabilizing olefin-containing hydrocarbon 011 againstdeterioration of its valuable properties which comprises adding to said011 a minor portion of a compound ing general structure:

wherein R and R are alkyl groups selected from the group consisting ofnormal butyl, isobutyl, secondary butyl and tertiary butyl groups.

4. An inhibitor for cracked gasoline comprising essentiallyp(n-butylamino)-phenyl-secondary-butyl ether.

'5. An inhibitor i'or cracked gasoline which comprises essentially acompound having the JOSEPH A. CHENICEK. ROBERT H. ROSENWALD.

gasoline compris-

